select "Identify and Attention Indicators"

select your disk, in this example "U0.1-P2/Z1-A9"

press enter, a '+' will be displayed

press F7 to switch on the light; the '+' will be replaced with an 'I'

Disabling the light:

press enter on the selected disk ("U0.1-P2/Z1-A9"), the 'I' will be replaced with a '+'

press F7: the '+' will be removed and the light is disabled

Mounting an NFS-share from a Linux-server

You might see (on the AIX system) the following error message:vmount: operation not permited
If that's the case, you might give:

nfso -o nfs_use_reserved_ports=1

(add -p to make it permanent) a try. It makes your AIX system use priviledged ports (< 1024), sometimes Linux systems enforce the use of those.
One can make the Linux host accept non-priviledged ports by adding the 'insecure' switch to the exported share in /etc/exports.

Compiling and using Postfix 2.5.6 on aix 6.1

Compiling Postfix 2.5.6 requires one small change. At line 215 of the file makedefs insert the following:

Install package 'X11.adt'

In ./include/SDL_stdinc.h remove #include <string.h>

IVM responds very slowly (half an hour per redraw)

This happens when you did not configure a DNS-server in the VIOS in which the IVM resides. Setting it to nameserver 127.0.0.1 in /etc/resolv.conf (or any other host on which no DNS is running) solves this. It looks as if the IVM still queries some DNS even if none is configured, if you have a host configured without any DNS running that responds with ICMP connection refused messages, the IVM knows it can stop trying.

Installing Debian in an LPAR

At least for Debian 4.0r4a one cannot put the filesystem containing the /etc in a logical volume! or else /etc/yaboot.conf cannot be found by the bootloader

One can not use a virtual optical drive (with VIOS 1.5) for the installation process: the installer will say that it cannot use the CD-ROM drive UPDATE 20080901: this problem seems to be fixed in the daily build of Debian Testing

Make sure you install the openssh-server package as it seems that it does not add a line to /etc/inittab for a console login

When while compiling you get the error that the file 'gnu/stubs-64.h' is missing then you need to install the package libc6-dev-ppc64

For some reason no getty-daemon is listening on the console so that by default you won't be able to logon via the console. For that to work add the following line to /etc/inittab and run 'kill -HUP 1' afterwards:

Create a journaled file system (NOT extendend or jfs2!) and enable the "Large File Enabled" option (in smitty).
This 2GB limit also applies when ulimit -f is set to unlimited(!).

Surf to "about:config" (without quotes) and then set all parameters starting with "security." to "true".

Linux installed in an LPAR doesn't reboot

Occasionally a Linux system crashes. Now when you want to reboot the LPAR in which it runs, do not choose 'reboot & write dump' as VIOS does not know how to handle the Linux swap-space (to store the memory dump). If you do, VIOS will give you an af003202 and af003302 error. So always select the 'reboot WITHOUT dump' option.